Art of heating and distillation



June 2, W GRAY ART OF HEATING AND DISTILLATION Filed Nov. 10, 1953wmmtgu QQQED IN VENTOR. 614/171; 67?

ATTORNEY.

Patented June 2, 1936 PATENT OFFICE ART OF HEATING AND DISTIILATIONJames W. Gray, Mountain Lakes, N. J.,

assignor to Luis de Flores Applicaflon November 10, 1933, Serial No.697,456 12,0laims. (01. man) The present invention relates toimprovements in the application of inert gaseous heating media, andparticularly steam, in distillation, heating, and other operationswherein it is desired to employ the inert gaseous heating mediumbotlfHor the heating of a material to be-treated by indirect heatexchange and in the treatment of the material as process steam; foreizample, in reducing the partial pressure of vaporization ofconstituents of the material in heating and distilla tion operations, inhydrolysis and the like. It will be fully understood from the followingdescription, illustrated by the accompanying drawing, in which thefigure shows diagrammatically and pmly in section apparatus suitable forcarrying the invention into effect in one application or em.- bodimentthereof.

{-In the embodiment shown in the drawing, the invention is illustratedin connection with the distillationrof an oily material, such, as thefatty acid stock resulting from the hydrolysis of fats, and with steamas the inert gaseous heating and process medium employed.

Referring more-particularly to the drawing,

the numeral indicates the chamber wherein ing or stripping plates. Thematerial to be subjected totreatment is supplied to the vessel or column5, preheated as hereinafter described, through the line I and theprocess steam or other inert gaseous medium is supplied to the vessel orcolumn 5 through the line 8, suitably near the bottom of 'the vessel andin such manner as to contact directly with the stock or material fedinto'the column. In the embodiment shown, a

vacuum is maintained on the column and distillation takes place, amixture of steam and vaporized fatty acids passing out of the columnthrough the line 9. Unvaporized material, which may be designated pitchor residue, is drawn 01? from a sump in the'bottom of the tower throughline H to a chamber or receiver l2 vented to the vessel or tower 5through the line l3. The pitch or residue collects in the chamber orvessel l2 and maybe discharged from the latter through the valved linell to an accumulator tank l5 which is provided with a valved dischargeline I 6 and a valved vent pipe ll. As is readily apparent, in case ofthe operation 'of the column or vase] 5 lmder vacuum, residual materialmay be accumulated i -the accumulatortank l5, its contents discharged 5and the accumulator then again closed oif from the atmosphere andconnected to the system. I

As indicated above, it is desired to preheat the fatty acid stock ormaterial entering the chamher or column 5 through the line 1 and it islike-' 10 wise desired to employ steam or other inert gaseous mediumwithin the column or vessel 5 in the process or operation conducted onthe material introduced therein. It is desirable that the heating of thefatty acid stock or other material introduced into the column 5 beconducted under carefully controlled conditions, by indirect heatexchange with an inert gaseous medium of the same' character as thatemployed in direct contact with the material under treatment change andin the process use thereof, it is necessary that there be an independentcontrol of the amounts and thermal content of the gaseous mediumemployed in each operation. In accordance with the present invention,such utilization of the gaseous heating medium may be secured andwithout employing a plurality of heating means therefor, anembodiment'of the method and means for the purpose being illustrated inthe drawing.

As shown in the drawing, the vapors with- 40}- drawn i'rom the chamberor column 5 through the line 9 pass to a partial condenser l8, which.

'is an indirect heat exchanger of any suitable form. From the partialcondenser l8, the cooled and partly condensed materials pass outthroughthe line l8eto a separator ,20, additional cooling being effected, ifdesired, byapp yin a spray of water or other suitable cooling agenttothe ma- -terial entering the separator 21! at the point 2| by means of aspray condenser. I'he separator 28 is provided with a vapor outlet line22 leading to the usual accessory apparatus, such asadditionalcondensing apparatus, if-desired, and alsotoavacmunpumpifthesystemistobeevacuated or to a pressure release valveif it isto be maintained under pressure. Such accessory means, being ofany suitabletype, is not illus trated. The separator 20 is also providedwit a suitable valved discharge line 23.

The fatty acid stock or material to be treated is supplied through theline 24, passing to the partial condenser l8, where it is somewhat presheated by indirect heat exchange with the vapors entering the partialcondenser l8 from the vessel or column 5 through the line 8. From thepartial condenser IS, the somewhat preheated feed stock or fatty acidstock passes through the line to the principal heater 26, which is anindirect heat exchanger wherein the fatty acid stock is heated to thedesired temperature for admission to the vessel or column 5. The heatedfatty acid stock passes from the heater 26 through the line 1 to thevessel 5, suitably'enteringth'e latter at an upper point in the columnin the case of the admission of the fatty acid stock to a stripping ordistillation column.

- The steam or inert gaseous medium employed lower pressure than thesteam entering through the line 21, then passes through the line 29 to asuperheating furnace 30, diagrammatically illustrated, andof anyconventional type, preferably.

a coil heating furnace. In the superheating furnace, the combined steamis brought to the desired temperature at which it is intended to employit in the heater 26 as a heating medium.

.The heated combined steam passes from the superheater 30 through theline 3|, from which a line 32 leads to the heater 26. Here the desiredproportion of steam is employed to heat the fatty acid stock or materialentering the vessel 5, the steam being thereby cooled. From the heater,

the used steam passes through the line 33 to in jector orthermo-compressor 28, where it is picked up and combined with the freshsteam supplied to the system and recirculated.

A part of the superheated steam leaving the superheater through the line3| enters the vessel or column 5 through the line 6, which joins theline 3| and is provided with a suitable control valve 34. In case it isdesired to reduce the temperature of the steam entering the vessel orcolumn 5 through the line 8, a portion of the steam leaving-the heater275 and cooled therein may be diverted from the line 33 through thevalved line 35' tothe line 8.

To further illustrate the present invention, the

the superheated steam as hereinafter set forth to a temperature of about490 F., at which temperature it is admitted in to the column 5 throughthe line I. 5

The column 5 is maintained under a vacuum say of about 24 inches at itsoutlet. Iirthe, operation of the column, it is found convenient to usesuperheated steam at a temperature of about 700 F., the requirements forthe colunm being somewhat in excess of 1400 lbs. of steam per hourinorder to secure the desired heating and partial pressure effect withinthe column 5. Suitably, about 1403 lbs. of steam per hour at 2 lbs.gauge'pressure are supplied to the column,

maintaining .a bottom temperature therein of about 600 Fl, the pressureof the steam being reduced to the column pressure on entering thelatter. The steam being supplied to the column at 700 F., the steamsuperheater 30 is so controlled as to maintain thetemperature of theseam at its outlet at approximately 700 F., and

2 lbs. gauge pressure. Under these conditions, it is found thatapproximately 1850 lbs. of steam per hour are required to effect thedesired heating in the heater 26. The total amount of steam required tobe delivered from the superheater is thus slightly more than 3250 lbs.P61111011!- In the operation in accordance with the present invention,the amount of steam required for heating purposes in the heater 26 iscontinuously recirculated through the heater 26 and the steamsuperheater 30, passing from the steam superheater through the lines 3|and 32 to the heater 26 and thence through the lines 33 and 29 back tothe superheater. At the injector or thermocompressor 28, a amount ofsteam equivalent to that required for p cess purposes is injected intothe cycle at a sufliciently high pressure to maintain the necessarypressure gradient on the steam for its circulation and delivery into thecolumn 5 and for utilization in the heater 26. In order to accomplishthis, about 1' l 001bs. of steam per hour in supplied through the line21 at a pressure of 90 lbs; gauge, the added steam combining at thethermo-compressor'26 with the steam beingrecirculated through the'heaterand amounting to about 1850 lbs. per hour, the combined-steam endetailsof an operation under commercial condipressure effects therein ashereinbefore set forth.

tions may be given, the material subjected to f treatment being a fattyacid stock and steam 1 moved from the column ,5 through the line 6. as

vapor, together with such amounts of steam as are employed for heatingand partial pressure .It.is readily apparent that the conditions ofoperations may be widely'varied. The temperature to which the steam issuperheated may, of course, be varied as desired. In the caseillustrated, it has been found satisfactory to deliver the superheatedsteam to the vessel 5 for process use and to the heater 26 for heatingpurposes at the same temperature. In general, it is found satisfactoryto deliver the heating medium to the heater-26 at any temperature foundconvenient for use in the vessel 5 for. process purposes. However, if itbe desired to deliver the heating medium to the heater 26 at a highertemperature than that at which it is desired to deliver it to the vessel5 for process'use, some the steam leaving the heater 26 at asubstantially reduced temperature through the line 33 may be divertedthrough the valved line 35 to enter the line 8 in any desired proportionin combination with steam derived directly from the superheater through:heating' cycle foruse for process purposes in the chamber '5, Under theconditions described in the specific embodiment hereinbefore set forth,the additional steam is supplied through the line 21 at a pressure of 90lbs. to maintain the desired ,conditions in the system. If a smallerproportion of steam he required for process purposes relative to thatrequired in the closedheating cycle, it may he supplied at a higherpressure; or ii a greater I referred to as the heating and processingagent,

proportion of added or process steam. be required, it may be supplied ata lower pressure.

It is likewise readily apparent that the fresh steam supplied to thesystem through the line 21 may be superheated before reaching theinjector or thermo-compressor 28, for example, by passing it or aportion of it through the line 35 into and through suitable coilsprovided in the superheater so, the superheated steam then reenteringthe line 27 through the line 31, suitable valves 38 and 39 beingprovided for the control of the steam passed through the superheater inthis manner.

As is readily apparent, for this purpose special 7 coils are required inthe steam superheater which must be eliminated therefrom it fresh,entering steam is not to be superheated. While in the specific example,steam has been it is readily apparent that other inert gases may beused. In steam distillation operations, the process may be employed inthe treatment of any fatty or oily material, mineral oils or in anydistillation process where the presence of inert gaseous medium isdesired for heating or partial pressure eiiects or both. Furthermore,the pres ent invention may be employed in connection with processingoperations generally where both heating and admission of an inertgaseous medium is desired for. agitation, reaction or partial pressureeffects.

I claim:

l. The method of heating and distilling fatty acid stocks wherein thefatty acid stocks are heated and subsequently discharged into a vesselwherein they are contacted with steam, the method which comprisesmaintaining, a circulation by passing steam through a superheater,

bringing the superheated steam into indirect heat exchange with fattyacid stock to heat the same and thereupon returningit to thesuperheater, withdrawing a portion of the steam leaving the superheaterand discharging it into said vessel in contact with the fatty acid stockunder treatwherein they are contacted with steam, the method whichcomprises maintaining a circulation by pasing steam through asuperheater; bringing. the superheated steam into indirect. heatexchange with fatty acid stock to heat the same and thereupon returningit to the superheater, withdrawing a portion of the steam leaving thesuperheater and discharging it into said vessel in contact with thefatty acid stock under treatment therein, with, said withdrawn steambefore entering the vessel, cooler steam diverted from said circulation,and injecting additional steam into that entering the superheater aftersaid indirect heat exchange, said additional steam.

being supplied under a pressure and in a manner to maintain thecirculation of the steam.

3. In the heating and processing of a. material wherein the saidmaterial is heated and subsequently discharged into a vessel to becontacted therein with heated gas, the steps which comprise circulatinga gaseous medium through a superheating means, then into indirect heatexchange with the said material to be heated and thereupon returning itto the superheating means, withdrawing a portion of the heated gaseousmedium leaving the superheating means and discharging it into contactwith the material under treatment in said vessel, and injectingadditional gaseous medium into that entering the,

superheater, said additional gaseous. medium being supplied under apressure and in a manner to maintain the circulation of the gaseousmedium.

4. In the heating and processing of a material wherein the said materialis heated and subsequently discharged into a vessel to be contactedchange with the said material to be heated and.

thereupon returning it to the superheating means, withdrawing a portionof the heated gas-w eous medium leaving the superheating means and thesuperheater in amount corresponding to the amount of heated gaseousmedium withdrawn and controlling the pressure of the additional gaseousmedium thus supplied to maintain the said circulation of the gaseous 5.The method of applying a gaseous medium for heating and processingpurposes which comprises maintaining a circulation of the'gaseousheating medium from a superheating means through a, heatv exchangedevice and back to said superheating means, withdrawing a portion of thegaseous medium leaving the supe'rheatlng means and discharging it into aprocessing means, and injecting into the gaseous medium entering thesuperheating means additional quantities of the gaseous mediumcorresponding to the portion withdrawn under a pressure higher than thatof the heating medium entering the heat exsaid circulation of the steam.v

7. The method of applying steam for heating and processing purposeswhich. comprises maintaining a circulation of steam from a superheatingmeans through a heat exchange device and.

back to'said superheating means, withdrawing a portion oi. thesuperheated steam leaving the superheating means and discharging it intoa processing means, injecting into the steam enterthe superheating meansfrom the heat ex- .the' heat exchange device and controlling thepressure of the steam thus suppliedto maintain circulation of the steam.8 method of applying steam for heating P ng purposeswhich comprisesmaina circulation of steam from a superheating meansthrough a heatexchange device and means for passing material to be treated through 25to said superheating means, withdrawing a, I portion oi. the superheatedsteam leaving the superheating means and discharging it into aprocessing means, diverting from the circulation additional steam afterleaving the heat exchange device and combining the additional steam thuswithdrawn with the previously withdrawn superheated steam, therebycontrolling the temperature of the latter,injecting into the steamentering the superheating means additional quantities oi steam under apressure higher than that of 9. In'steain heating and distillationapparatus,

a "distillation vessel, a heat-exchange device,{

means'ior passing material to be treated through :fsaid'heat-e'xchangedevice into said vessel, a steam, superheater, means for conductingsuperheated steamfrom said superheater to said heatexchange device toheat the material passing L therethrough, means for passing a ortion ofthe superheated steam leaving the superheater into said distillationvessel, and means for withdrawsuppliedfto the distillation vesselcombined with thes'teem withdrawn from said heat-exchange.devi'oegthecombined steam entering the super-- heater.

10.1111 apparatus for heating and processing a liquidity means 01' aninert gaseous medium,

means for superheating said gaseous medium, a

heat-receiving device through which the liquid is adapted to pass, meansfor discharging heated gaseous medium from the said superheating means,means for removing a'portion oi the heated gaseous medium dischargedfrom said superheating means and supplying it to processing means, meansfor conducting the remainder of said heated gaseous medium to theheatreceiving device to heat the liquid passing therethrough, anduneansfor returning the gaseous medium supplied'to said heat-receiving deviceto the superheating means, said returning means including athermo-compressor, means for supplying additional gaseous medium to saidthermocompressor under pressure in amount to compensate forsubstantially all that removed, the gaseous medium thus returned beingcombined with the additional gaseous medium supplied to saidthermo-co'mpressonand means for conducting the combined gaseous mediumto said superheating device.

l-l. In steamheating and distillation apparatus, a distillation-vessel,a heat-exchange device,

said heat-exchange device into said vessel, a steam superheater, meansfor conducting superheated steam from said superheater to saidheatexchange device to heat the material passing therethrough, means forpassing a portion of the superheated steam leaving the superheater intosaid distillation vessel, and means for withdrawing steamirom the saidheat-exchange device and returning it to the superheater, said meansincluding an injector connected to said heat ex-'. change device towithdraw steam therefrom and means for supplying additional steam underpres:

sure-t0 a separate heating means in the superheater to compensate forthe steam supplied to the distillation vessel, and means for conveyingsaid additional steam to .saidinjector to com-- blue with the steamwithdrawn from the .heatexchange device, the combined steam. enteringthe superheater.

' 12. The method of applying a gaseous medium for heating and processingpurposes which comprises maintaining a circulation of the gaseousheating medium from a superheating means through a heat exchange deviceand back to said superheating means, withdrawing a portion of thegaseous medium leaving the superheating means and discharging it intoaprocessingmeans, and injecting by jet action additionarquantities ofthe gaseous heating medium fiito that entering the superheating meanssubstantially equivalent to v the portion withdrawn and under a pressurehigher than that of the heating medium enter-' ing the heat-exchangedevice and in a manner to maintain by such jet action the said circula-

